Protechsoft Technologies Interview Questions and Answers

C is a procedural programming language, while C++ is an object-oriented programming language that is an extension of C.

• C is a procedural programming language, focusing on functions and procedures.

• C++ is an object-oriented programming language, allowing for classes, objects, and inheritance.

• C++ is an extension of C, adding features like classes, templates, and exception handling.

To find the 3rd maximum salary, we can use SQL queries to filter and sort salary data effectively.

• Use the DISTINCT keyword to avoid duplicate salaries: SELECT DISTINCT salary FROM employees.

• Sort the salaries in descending order: SELECT DISTINCT salary FROM employees ORDER BY salary DESC.

• Use LIMIT or FETCH to get the 3rd salary: SELECT DISTINCT salary FROM employees ORDER BY salary DESC LIMIT 1 OFFSET 2.

Program to generate Fibonacci series

• Start with two variables initialized to 0 and 1

• Loop through desired number of terms and calculate next term by adding previous two terms

• Store each term in an array

• Return the array of Fibonacci series

Program for different types of books using Inheritance Concept

• Create a Book class as the parent class

• Create Paperbook, E-book, and Audiobook classes as child classes

• Inherit properties and methods from the Book class

• Add unique properties and methods to each child class

• Example: Paperbook class can have a property for number of pages

• Example: E-book class can have a property for file format

An abstract class is a class that cannot be instantiated and is meant to be subclassed.

• An abstract class can have abstract methods that must be implemented by its subclasses.

• Abstract classes can also have non-abstract methods and variables.

• Abstract classes provide a way to define common behavior and characteristics for a group of related classes.

• Example: The abstract class 'Animal' can have abstract method 'makeSo...read more

The 'this' operator refers to the object that is currently executing the code.

• The value of 'this' depends on how a function is called.

• In a method, 'this' refers to the object that owns the method.

• In a regular function, 'this' refers to the global object (window in a browser).

• In an event handler, 'this' refers to the element that received the event.

• The value of 'this' can be explicitly set using call(), apply(), or...read more

The == operator checks for equality, while the === operator checks for both equality and type.

• The == operator performs type coercion, meaning it converts the operands to a common type before comparison.

• The === operator does not perform type coercion and requires both the value and type to be the same for equality.

• For example, 1 == '1' returns true because the operands are coerced to the same type, but 1 === '1' re...read more

Testing is the process of evaluating a system or component to determine if it meets specified requirements.

• Testing is done to identify defects or errors in software.

• It involves executing a program or system with the intent of finding bugs.

• Testing ensures that the software meets the desired quality standards.

• It includes various techniques like functional testing, performance testing, etc.

• Test cases are designed to ...read more